Six Nations 2015: Wales-Ireland makes Gareth Thomas miss rugby

In his 2015 Six Nations column for the BBC Scrum V website, former Wales captain Gareth Thomas looks ahead to Saturday's mouth-watering match against Grand Slam-chasing Ireland in Cardiff. If Wales win, there could then be a three-way race for the tournament title.

Since I retired from rugby I've never really missed playing at all, because I knew it was time for me to retire.

But there's something about this game, Wales against Ireland, that has got me missing rugby.

It has got me wanting to be a part of this week with Wales, part of this build-up and a part of Saturday's game.

I feel it's going to be something really special because there seems to be so much on it: so much pressure, so much excitement, so much anticipation.

The two best fly-halves in Europe

I'm not surprised Wales coach Warren Gatland has stuck with the same team. Two weeks ago against France was without a shadow of a doubt their best performance of this Six Nations so far.

Apart from a few enforced changes on the bench, why would you change a winning team?

There's no place once again for Alex Cuthbert - a British and Irish Lion - but it's a case of 'we could be talking about Liam Williams, we could be talking about George North' missing out.

Wales are lucky that we're blessed with an amazing array of talent in the back three.

The fact that full-back Leigh Halfpenny cements his place with his kicking is a given, so the only spaces in the back three up for grabs are on the wings.

Liam Williams has been pushing and pushing for a place and he did extremely well against Scotland and France, so you can't really justify dropping him.

You need cover on the bench but you need to look at all aspects of who could get injured, who could come in where, and with Cuthbert being an out-and-out winger that counts against him.

I'm glad that Ireland will be back to something close to full strength, with Johnny Sexton, Jamie Heaslip, Sean O'Brien and Jared Payne all cleared to face Wales.

It's really positive for the game - for the actual match - that all these big guys are going to be there.

I don't know whether I should be pleased, but I feel that this game now - on the back of what Ireland produced against England and Wales' performance in Paris - I want it to be a fair reflection, I don't want there to be any excuses.

More influential than anyone is Sexton; he's stepped back into the fly-half role as if he's never been out and he's vital to Ireland.

I want to see him and Dan Biggar go head-to-head, because Biggar so far has been outstanding for Wales - potentially they're the two best fly-halves in Europe.

People want to see the other big guns, players like flankers Sam Warburton and Sean O'Brien, coming up against each other and see how they're going to compete with each other at the breakdown.

Individual battles all over the field

The breakdown will be a massive area but Ireland don't always contest at rucks, they are quite happy sometimes to let the opposition have the ball.

They play a very sensible, educated game and the half-back positions are tactically very, very vital to do that.

But those positions can only have an impact on the game if you have a solid scrum and a solid line-out.

Luke Charteris coming in at lock for Wales was a great selection by Gatland against France and he showed his effectiveness in stopping the driving line-out.

He's coming up against a guy in Devin Toner who in feet and inches is a match - the Irishman is an inch taller at 6ft 10in (6.08m) - and that's where this game is so intriguing, you have matches all over the field.

If both teams are quite solid on their own ball - which I expect them to be - then it will be down to the nines and 10s and how they dictate the game, how they kick out of hand and the areas of the field they kick into.

Schmidt and Gatland "are very conflicting coaches but both very successful in the way they approach the game"

A massive thing in modern-day rugby is analysis, so what Wales did against France, Ireland are going to be watching and making sure Wales can't do that against them.

Likewise what Ireland did to England, when their kicking game saw them dominate much of the match, Wales are going to be sitting down and planning how to stop that happening again.

As much as it's a battle of players on the field, you've got two very astute coaches up against each other.

Ireland coach Joe Schmidt knows what he has, he knows his players and what they're capable of, but ultimately he finds a way to stop the other team playing.

That means they change the way they play most weeks, which makes them very hard to predict, whereas I think Wales are very predictable.

Wales are very difficult to stop, however, even though everybody knows exactly what they're going to do.

I suppose Schmidt and Gatland are very conflicting coaches but both very successful in the way that they approach the game.

Cardiff: Ireland's home away from home

Even when I was playing it was always a strange thing with Ireland; Wales would go to Ireland and win and Ireland would always come to Wales and win.

It was a strange thing because Dublin and Cardiff are both tough places to go and get an away win.

It's even more so now with the Pro12 and the players playing against each other constantly - they know each other's game so well.

"Off the pitch we're so similar, there's respect, but no one is going to give an inch on the pitch"

As Ireland know how to win at the Millennium Stadium it's not as daunting for the Irish team as it is for some other sides.

It's a great atmosphere, it's a great place to play rugby and psychologically can provide a good points advantage for Wales.

But when it comes to the Ireland team that advantage becomes irrelevant; when you break the 'bogey' of being able to win there, and win there on a regular basis, then it becomes a motivating factor for your team rather than something to be afraid of.

The Welsh and Irish are two cultures that are very similar and two cultures that are very proud, very passionate and want to stand their own ground.

That means that there's a sense of being able to get on with each other off the pitch because we're so similar, there's respect, but also with that stubbornness and that pride no one is going to give an inch on the pitch.

Ultimately you have to then battle for that inch, and that's where the fierceness and rivalry comes from.

World Cup form on the line

This Six Nations is turning into an amazing competition, not only for the outcome of the title or the Grand Slam but for the World Cup.

People were talking in the autumn about whether Wales could beat Australia, South Africa and New Zealand, but for me the Six Nations is a better benchmark for where you are because it's a tournament.

It's structured similarly to the World Cup and I think Ireland are, without a shadow of a doubt within the last 10 games, the best team in Europe results-wise.

So this game is huge not just for potentially deciding the Grand Slam and the Championship, but to see really where Wales are in the standings of the European teams.

It doesn't need any extra spice and to think it could yet go down to the final day shows that this tournament is growing in strength.

Gareth Thomas was speaking to BBC Wales Sport's Bruce Pope